<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>let</title>
</head>
<body>
    <script>
        //声明变量
        let a;
        let b,c,d;
        let e = 100;
        let f = 521 ,g = 'iloveyou',h=[];

        //1 ，变量不能重复声明
        // let star = "罗志祥";
        // let star = "ss";

        //2 块级作用域，全局，函数，eval
        //3 不存在变量提升

        // {
        //     let gtil = '周扬青';

        // }
        // console.log(girl)

        //4，不影响作用域链

        {
            let school = "尚硅谷";
            function fn(){
                console.log(school);
            }

            fn();
        }

    </script>
</body>
</html>